The class of polyamide polymers which is the major component of the blends of the invention has been known for many years. These polymers, also known as Nylons, have gained extensive commercial recognition in the production of numerous types of objects produced by many of the methods conventional for the processing of such thermoplastic polymers. Although the polyamides are useful in the formation of three-dimensional objects such as gears and motor housings, the most frequent use is probably in the production of fibers and filaments and the yarns and fabrics prepared therefrom. There are, however, certain limitations imposed by the properties of the polyamide polymers which limit their use in some applications. For example, polyamides exhibit low melt viscosity and elasticity which limit the usage of the polyamides in applications which require significant melt strength, e.g., applications such as thermoforming and blow molding. It would be of advantage to retain the more desirable properties of the polyamide polymers while improving other properties such as melt viscosity and elasticity in the melt. These advantages are often accomplished through the provision of a polymer blend.
Blends of polyamide polymers are known whereby the properties of the polyamide polymer have been modified. For example, Epstein, U.S. Pat. No. 4,174,358, describes blends of a number of polymers in a polyamide matrix which are said to show improved ductility and toughness. Blends wherein the polyamide polymer is a minor component in a blend which is predominantly linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon are disclosed in U.S. Pat. No. 4,839,437. These latter blends which additionally contain an acidic polymer containing moieties of .alpha.-olefin and .alpha.,.beta.-ethylenically unsaturated carboxylic acid are disclosed in copending U.S. patent application Ser. No. 429,913, filed Oct. 31, 1989. The presence of the minor components serves to improve certain of the properties of the linear alternating polymer. It has now been found that polymeric blends wherein the polyamide is the major component demonstrate improved properties upon blending with such linear alternating polymers and such acidic polymers.